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Background: Dehydration through exercise induces physiological and metabolic changes which may impair health, limit exercise capacity, and negatively affect athletic performance. However, our understanding of the underlying mechanisms driving dehydration-induced exercise impairment is limited. Furthermore, there appears to be a high inter-individual variability in physiological response to hypohydration. Metabolomics analysis can provide valuable insight into cellular signaling pathways and biochemical processes that underlie the physiological and practical impacts of dehydrating exercise, providing the foundation for personalized exercise and hydration recommendations based on an individual’s metabolic profile. Study Design: Accordingly, we subjected 10 male athletes to a dehydrating exercise protocol while measuring exercise performance, hydration status and body morphometrics. We metabolically profiled blood samples taken before and after a dehydrating exercise, and again after a rehydration period. Salivary and plasma osmolality were used as indicators of dehydration status; A VO2max test and cognitive measures (Trail Making Test and Stroop Test) were used to define the extent of performance deficit. Results: Salivary osmolality and plasma osmolality both increased throughout the dehydration protocol (Salivary: 92.9 ± 30.2 mmol/kg at Baseline vs 341.6 ± 129.3 mmol/kg at Post-Exercise, p = 0.0033; Plasma: 302.5 ± 8.7 mmol/kg at Baseline vs 315.4 ± 8.8 mmol/kg at Post-Exercise, p = 0.0122), and returned to baseline levels after rehydration (Salivary: 93.8 ± 21.3 mmol/kg at Post-Hydration vs 92.9 ± 30.2 mmol/kg at Baseline, p > 0.9999; Plasma: 302.6 ± 8.0 mmol/kg at Post-Hydration vs 302.5 ± 8.7 mmol/kg at Baseline, p > 0.9999), indicating that the body fluid loss during exercise significantly impaired body fluid balance. VO2max, on average, showed a significant decrease (-7.7 ± 6.7%) from Baseline to the Post-Exercise time point (43.7 ± 6.4 mmol O2/min/kg vs 40.6

Osteoporosis, a major public health problem, likely has its origins in childhood. During periods of rapid skeletal growth, diet may influence accrual of bone mineral density (BMD) and adult bone health. This study used novel approaches in bone imaging to further characterize optimal skeletal development and enhance our understanding of key dietary components that influence attainment of peak bone mass (PBM) and contribute to determinants of peak bone strength in peri-pubertal females. The use of a validated food-frequency questionnaire (FFQ) enabled the influence of usual dietary intake on bone parameters to be examined.This study examined the relationship of dietary intake of micronutrients and bone macro-architectural structure in peri-pubertal girls. This study suggested that vitamin C and zinc intake are associated with objective measures of bone status in 4th, but not 6th grade girls. This indicates potential differences in micronutrient and bone associations at various age-associated stages of bone maturation.The impact of dietary fat on peri-pubertal skeletal growth is not well characterized. This study examined relationships of select dietary fatty acid (FA) intakes and measures of bone status in peri-pubertal girls. This study suggested that MUFA, total PUFA, n-6 and linoleic acid (LA) are inversely associated with bone status prior to menarche, but composition of dietary fat may be more important during the early-pubertal years. Decreased intakes of n-6 PUFA may benefit bone health in young girls.The impact of a dietary protein on volumetric bone mineral density (vBMD), bone mineral content (BMC) and bone strength throughout maturation remains controversial. Given evidence of both anabolic and catabolic affects of protein on bone health, this study examined relations of dietary protein from different sources with bone parameters in peri-pubertal girls. This study showed that dietary protein intake is related to higher trabecular but not cortical vBMD, BMC